The diagnosis of the pelvic actinomycosis is seldom made preoperatively because of no reliable or specific clinical manifestation which has tendency to mimic advanced gynecological malignancy and the relative infrequency of the disease. To explore the method for improvement of preoperative diagnosis and possibility of avoiding the surgical management of pelvic actinomycosis, we collected and summarized the data of age, parity, state of menopause, history of intrauterine device (IUD) use, symptoms, laboratory findings, radiologic findings, provisional diagnosis and treatment from 14 cases diagnosed pathologically and treated in Hanyang University Hospital from 2000 to 2007. Eleven (78.6%) of 14 cases were IUD users. Most common complaints were lower abdominal pain (71.4%) and vaginal discharge (57.1%) which were followed by fever (28.6%) and back pain (28.6%). Four cases (28.6%) were identified as pelvic actinomycosis before operation and in 3 cases (21.4%) malignancy was provisional preoperative diagnosis. Pelvic actinomycosis was suspected via abdominal computed tomography (CT) or cervicovaginal cytology and confirmed via endometrial biopsy or fine needle aspiration biopsy. Two cases that were diagnosed before operation and received only antibiotics therapy had no recurrence. It was suggested that pelvic actinomycosis could be suspected via abdominal CT and cervicovaginal cytology in IUD users, and endometrial biopsy and fine needle aspiration biopsy may help establish the diagnosis before the operation. Adequate preoperative antibiotics therapy could make extensive exploratory surgery avoided or conservative surgery feasible.